1. Field of the Invention
This invention relates to a support for a web forming machine. More particularly, this invention relates to a support for a web forming machine which allows for vertical adjustment of a web forming belt with respect to at least one die head positioned above the web forming belt, and allows for tilting of the web forming belt.
2. Description of Prior Art
Conventional supports or guide posts for supporting a web forming machine prevent any lateral or vertical movement of the web forming machine. Further, because the conventional guide posts also prevent any rotational movement or tilting of the web forming machine, the web forming belt is not allowed to tilt or slope with respect to a base of the web forming machine.
In order to provide for tilting of the conventional web forming machines, as is often desired during polymer extrusion applications, the conventional guide posts must be mechanically bent. Thus, these guide posts are generally constructed of an easily bendable material. As a result of using easily bendable materials for the construction of the guide posts, the guide posts do not provide proper lateral restraint for the web forming machine. Additionally, mechanical binding and/or bending of the web forming belt occurs as it moves across the conventional guide posts. Further, the web forming belt cannot be vertically positioned and/or adjusted with respect to the die heads using conventional guide posts.
It is apparent that there is a need for a support for a web forming machine which allows the vertical positioning and/or adjustment of the web forming belt with respect to the die heads positioned above the web forming belt.
It is also apparent that there is a need for a support for a web forming machine which allows for rotational or axial positioning and/or adjustment of the support to prevent mechanical binding and/or bending of the web forming belt as it moves across the supports.
In response to the discussed difficulties and problems encountered in the prior art, a support for a web forming machine which provides linear motion along a y-axis and rotational motion about a x-axis perpendicular to the y-axis, has been discovered. The support for the web forming machine allows a web forming belt to be vertically positioned with respect to die heads positioned along the length of the web forming belt. Further, the support can be axially or rotationally positioned to maintain an outer surface of the web forming belt in a generally flat or planar orientation and to prevent mechanical binding and/or bending of the web forming belt as the web forming belt moves across the support.
During polymer extrusion applications, it is often desirable to increase or decrease the vertical distance between the web forming belt and the successive die heads. For example, a first vertical distance between a first die head and the web forming belt may be about 12 inches, a second vertical distance between a second die head, downstream from the first die head, and the web forming belt may be about 13 inches, and a third vertical distance between a third die head, downstream from the second die head, and the web forming belt may be about 14 inches. As the vertical distances between successive die heads and the web forming belt increase or decrease, the web forming belt will have either a positive or negative slope, respectively, with respect to a base of the web forming machine.
The support according to this invention allows linear motion along the y-axis defined by the length of the guide shaft while preventing linear motion along the x-axis and a z-axis, e.g. the two axes perpendicular to the y-axis. Further, the support allows rotational or axial motion about the x-axis perpendicular to the y-axis but prevents rotational motion about the y-axis and the z-axis.
With the foregoing in mind, it is a feature and advantage of this invention to provide a support for a web forming machine which allows for the vertical adjustment of a web forming belt with respect to a die head of the web forming machine while preventing either lateral or longitudinal movement of the web forming machine.
It is also a feature and advantage of this invention to provide a support for a web forming machine which allows for tilting or sloping of a web forming belt to vary a distance between the web forming belt and successive die heads and prevent subsequent mechanical binding and/or bending of the web forming belt.